Such a device is disclosed in European patent application EP-A1-1 411 008. The device described in the document comprises tilting means of relatively compact construction, as appears in particular from FIG. 4 of EP-A1-1 411 008. Accordingly, the support platform is positioned relatively close above the level at which the conveying means support the leg members. However, there may also be reasons which it is desirable that the support platforms be spaced a greater distance above the level of the support means. Such a reason may be the fact that cheeks are used on the facing ends of the support platforms, such as those described in European patent application EP-A1-960838. The cheeks are indicated at 6 and 8 in the aforesaid document. During tilting of a support platform provided with the associated cheeks, the downwardly extending cheeks need space.